Optimizing Lane Widths to Achieve a Balance of Safety, Operations, and User Needs

Flexibility in roadway lane width requirements allows agencies to plan, design, and construct roadways that are appropriate for all roadway users and the context in which the roadway exists. Posted speed limits, truck and bus volumes, safe interaction of users, and spatial needs for all roadway users and features are the key variables to help determine suitable vehicular, bike, parking, and sidewalk widths. Lane width is merely one cross sectional element of the roadway; however, historically the presumed inflexibility of lane width—notably the 12-foot (ft.) lane—has often been the limiting factor of constructing roadways that provide an appropriate balance of all roadway users and functions within an oftentimes restricted right of way.